Method of recovering electrode material and method of manufacturing recycled electricity storage device

Abstract

A method of recovering electrode materials includes: a preparing step of preparing an electrode assembly or an electrode sheet, the electrode assembly and the electrode sheet including a current collector and an electrode active material layer formed on the current collector and containing an electrode active material; a dissolving step of immersing the electrode assembly or the electrode sheet in an etchant solution that dissolves the current collector; and a separating step of separating a precipitate containing the electrode active material from the etchant solution in which the current collector is dissolved.

1 . A method of recovering electrode materials, comprising:
 a preparing step of preparing an electrode assembly or an electrode sheet, the electrode assembly and the electrode sheet each including a current collector and an electrode active material layer formed on the current collector and containing an electrode active material;   a dissolving step of immersing the electrode assembly or the electrode sheet in an etchant solution that dissolves the current collector; and   a separating step of separating a precipitate containing the electrode active material from the etchant solution in which the current collector is dissolved.   
     
     
         2 . The method of recovering electrode materials according to  claim 1 , wherein:
 the preparing step includes preparing the electrode sheet;   the electrode sheet is a positive electrode sheet including a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector and containing a positive electrode active material;   the dissolving step uses an etchant solution that dissolves the positive electrode current collector; and   the separating step includes separating a precipitate containing the positive electrode active material from the etchant solution in which the positive electrode current collector is dissolved.   
     
     
         3 . The method of recovering electrode materials according to  claim 2 , wherein the positive electrode current collector includes aluminum or an aluminum alloy. 
     
     
         4 . The method of recovering electrode materials according to  claim 1 , wherein:
 the preparing step includes preparing the electrode sheet;   the electrode sheet is a negative electrode sheet including a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector and containing a negative electrode active material;   the dissolving step uses an etchant solution that dissolves the negative electrode current collector; and   the separating step includes separating a precipitate containing the negative electrode active material from the etchant solution in which the negative electrode current collector is dissolved.   
     
     
         5 . The method of recovering electrode materials according to  claim 4 , wherein the negative electrode current collector includes copper or a copper alloy. 
     
     
         6 . The method of recovering electrode materials according to  claim 1 , wherein:
 the preparing step includes preparing an electrode assembly;   the electrode assembly includes:
 a positive electrode current collector; 
 a positive electrode active material layer formed on the positive electrode current collector and containing a positive electrode active material; 
 a negative electrode current collector; and 
 a negative electrode active material layer formed on the negative electrode current collector and containing a negative electrode active material; 
   the dissolving step uses an etchant solution that dissolves the positive electrode current collector and negative electrode current collector of the electrode assembly; and   the separating step includes separating a precipitate containing the positive electrode active material and the negative electrode active material from the etchant solution in which the positive electrode current collector and the negative electrode current collector are dissolved.   
     
     
         7 . The method of recovering electrode materials according to  claim 6 , wherein the positive electrode current collector includes aluminum or an aluminum alloy, and the negative electrode current collector includes copper or a copper alloy. 
     
     
         8 . The method of recovering electrode materials according to  claim 1 , wherein the etchant solution is at least one of aqueous lithium hydroxide solution and aqueous sodium hydroxide solution. 
     
     
         9 . The method of recovering electrode materials according to  claim 1 , wherein the etchant solution is an aqueous iron chloride solution. 
     
     
         10 . The method of recovering electrode materials according to  claim 6 , wherein the preparing step includes removing the electrode assembly from an electricity storage device including a battery case accommodating the electrode assembly. 
     
     
         11 . The method of recovering electrode materials according to  claim 2 , wherein:
 the preparing step includes:   removing the electrode assembly from an electricity storage device including a battery case accommodating the electrode assembly; and   further separating the positive electrode sheet from the electrode assembly.   
     
     
         12 . The method of recovering electrode materials according to  claim 4 , wherein:
 the preparing step includes:   removing the electrode assembly from an electricity storage device including a battery case accommodating the electrode assembly; and   further separating the negative electrode sheet from the electrode assembly.   
     
     
         13 . The method of recovering electrode materials according to  claim 10 , wherein:
 the battery case includes an opening;
 a sealing plate closing the opening and to which an electrode terminal is attached, a portion of the electrode terminal being connected to the electrode assembly in the battery case; and 
 a bottom plate opposed to the sealing plate; and 
   the preparing step includes:
 disconnecting the sealing plate and the bottom plate from the battery case, to form a pair of openings; and 
 pushing the electrode assembly out from one of the pair of openings toward the other one, to remove the electrode assembly from the battery case. 
   
     
     
         14 . The method of recovering electrode materials according to  claim 13 , wherein, in the preparing step, the sealing plate and the bottom plate are disconnected from the battery case by water jet cutting. 
     
     
         15 . The method of recovering electrode materials according to  claim 1 , further comprising, after the preparing step and before the dissolving step, a crushing step of crushing the electrode assembly or the electrode sheet. 
     
     
         16 . A method of manufacturing a recycled electricity storage device, comprising:
 a preparing step of preparing an electrode assembly or an electrode sheet, the electrode assembly and the electrode sheet each including a current collector and an electrode active material layer formed on the current collector and containing an electrode active material;   a dissolving step of immersing the electrode assembly or the electrode sheet in an etchant solution that dissolves the current collector;   a separating step of separating a precipitate containing the electrode active material from the etchant solution in which the current collector is dissolved;   a recovering step of recovering an electrode material containing at least one of the positive electrode active material and the negative electrode active material from the precipitate; and   a constructing step of constructing an electricity storage device using the electrode material.